Module 'subprocess32' has no 'Popen' member

### Steps to reproduce
1. Create a file named `test.py` containing:
```python
import subprocess32
subprocess32.Popen(["echo"])
```
2. Run `pylint test.py`

### Current behavior

```
test.py:2:0: E1101: Module 'subprocess32' has no 'Popen' member (no-member)
```

### Expected behavior

No error

### Astroid version

`2.3.3`, `2.4.2` and `2.5` all exhibit this behaviour.

Reproduce the report with the shown test.py contents and run pylint to confirm the no-member error for subprocess32.Popen. Trace astroid's handling of the subprocess32 module and its Popen member; done means the example produces no error.

Written by the indexing model from the issue text.